There are some positives and negatives here and we as a user and reseller have experienced both.
The VoiceMaster solution does offer very good value for money (we used to sell similar packages 3-5 years ago for $500k+) and does offer modules to cover most eventualities. On the down side they can be difficult to deal with directly.
We have provided a lot of on-site training for companies around the world on the VoiceMaster product, and when it is set up fully it is a great system.
The best thing to do is find yourself a reseller who can provide you local support in your time-zone, or a company that offers true 24/7 cover – obviously the latter comes at a premium.
If you have any questions I’d be glad to help.